In recent years, in order to transfer (picking and placing) a relatively thin workpiece such as a solar cell wafer or a lithium ion battery electrode, a transfer device that uses a non-contact holding device capable of holding a workpiece without directly contacting the workpiece has been used. As such a transfer device using a non-contact holding device, Patent Literature 1 (Japanese Patent Application Publication No. 2004-83180) discloses a transporting device (a transfer device) that uses a Bernoulli chuck to generate suction force by ejecting high-pressure air.
The transfer device disclosed in Patent Literature 1 removes a sheet-form board (workpiece) from a stage in the form of a flat plate and transfers the sheet-form board. The transfer device has a Bernoulli chuck functioning as suction means, and a control guide that is positioned so as to abut with an end part of the workpiece disposed on the flat stage and controls the position of the workpiece. This control guide includes a controller provided, with an inclined surface, wherein the end part of the workpiece is brought into abutment with the inclined surface of the controller, thereby preventing Bernoulli chuck and the sheet-form workpiece from coming into contact with each other when the workpiece is suctioned by the Bernoulli chuck. The control guide further restricts a planar movement of the workpiece by means of the inclined surface of the controller when the workpiece is transported while being suctioned.
Incidentally, a solar cell wafer or a lithium ion battery electrode is thin in thickness and fragile as a workpiece. However, the transfer device disclosed in Patent Literature 1 brings the end part of the sheet-form workpiece into abutment with the inclined surface of the controller as described above, to prevent the Bernoulli chuck and the sheet-form board from coming into contact with each other when the Bernoulli chuck suctions the sheet-form board. Therefore, there is a possibility that the sheet-form workpiece cracks or is damaged in different manners when the workpiece is removed from the flat stage.
In addition, if the sheet-form workpiece shifts relative to the positions of the Bernoulli chuck and the control guide when being removed from the flat stage in this transfer device disclosed, in Patent Literature 1, the inclined surface formed in the controller might rub a rim part of the workpiece. Rubbing and consequently damaging the rim part of the workpiece when removing and holding the workpiece (picking up) or mounting the workpiece (placing) results in deterioration of the performance of the solar cell wafer, which is the workpiece.